Push button switch



FIG. 1 is a front elevational view of a push button switch showing my new design, the rear view being identical;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a left side elevational view thereof, the right side being identical; and

FIG. 5 is a top perspective view thereof. 

The ornamental design for a push button switch, as shown and described. 